The present invention relates to a method and a device for working, by metal-cutting processes, the surfaces of profiles having a non-circular contour, in which, starting out from a blank contour, material is removed from the surface to give the profile a desired contour by moving the processing tool and the profile relative to each other in such a manner that the portion of the processing tool which is at any time in engagement with the surface is moved along the contour in a path-controlled manner, while on the other hand the tool is advanced in feed-controlled manner by the surface distance between the blank contour and the desired contour.
Methods of this type have previously been known and are used, for example, for grinding the cams of camshafts.
In the case of the known method, the camshaft is arranged to rotate about a fixed axis, and a grinding wheel is seated to rotate about an axis extending in parallel to the camshaft axis. In order to obtain a pre-determined desired contour of the cams, the distance between the axis of the grinding wheel and the camshaft axis is varied while the camshaft rotates slowly so that the surface section of the grinding wheel which is at any time in engagement with the workpiece removes so much material from the surface of the cam that finally the desired contour is obtained.
The variation of the distance between the axis of the grinding wheel and the camshaft axis is dependent upon two marginal conditions:
On the one hand, the distance has to be varied in order to allow for the particular contour of each cam to be processed. This component of the entire variation of the distance is called "path-controlled operation".
On the other hand, however, one also has to vary the distance of the axes in order to ensure a certain infeed, i.e. an advancing motion of the tool towards the cam to be processed by the difference between the blank dimension and the desired dimension. This component of the variation of the distance is called "feed-controlled operation".